Hi just thought I would post this. It kinda helps.
1st - set your Xbox 360 to 60hz. There are some games that show small borders when in 50hz, meaning the image is the same width but shorter so it makes things look a little wider... as in circles are no longer perfect circles. There is less flicker in 60hz. If the TV shows loads of overlayed flickering images change it back to 50hz
Now I don't know if this is just my TV or what, but IF you set it to 60hz, it wont do stuff encoded in 50hz properly, like PAL DVDs. If you put in a PAL DVD when the system is set to 60hz, you will get the annoying overlayed flickering. So for DVD playback, set your 360 back to 50hz.
Any feedback on if this happens to your TV would be appreciated (as in when the 360 is set to 60hz will it still play DVDs properly). I ahve only tried with a few DVDs...